Dosage system of solid products for packing machines

ABSTRACT

Dosage system applied to automatic packaging machinery, capable of measuring the mass of solid products in bulk and adjusting the final mass of the package to be baled, so that the average masses of each package result in a value pre-established, as well as the standard deviation of the masses average result in a value within a tolerance range previously defined.

FIELD OF THE INVENTION

This invention, which belongs to the field of engineering of mechanicaldevices of industrial use, covers a solid product provision systemapplied to automatic packaging machinery, using the final mass controlof the batch composed by packages whose average weight is the target ofthe dosage system.

BACKGROUND OF THE INVENTION

The automatic packing machines have historically aimed at making thecomposition of the packages filling the container with the product to bepacked, forming what is called the primary packaging. Its final weightor volume must be consistent with the values previously establishedand/or programmed and are controlled at the time of filling the packagewith the product.

Thus, devices for measuring mass and volume may be associated to thepackaging machinery, in order to enable the filling of the package whilemaintaining the weight or volume of the package within the desiredspecifications, with the least possible deviation.

When it comes to fluid products such as liquids or pastes, the controlis easier, since you can adjust the amount of the product to be packedmore precisely, halting the package supply at the exact point where thevolume or mass reach the desired value.

In the case of solid products, however, this task presents an additionaldifficulty related to the indivisible mass of the unit element of thesolid product. For example, beans and bullets, which individually have aminimum mass that can not be divided. That is, when forming a package ofa solid product, the mass of the particle can have a value greater thanthe one desired to form the final mass of the package. For instance, abullet of about 7 g can contribute with a significant additional mass ina package of gum that requires 3 g to compound its standard mass. Thusthere will be a quantity that exceeds the standard weight of the packagein question and it may be considered in the accountability of theaverage weight of the packages of a certain batch or a certain bale.

Therefore, it is necessary that the mass control system, combined withmeasurement devices, may account for these amounts of particulateproducts, surplus or missing, to compensate through the process ofpackaging the batch of product, ensuring that the mass of each packageshould be as close as possible to the limit, and the average package ofthe lot to be formed, meaning that the standard deviation is minimized.

Additionally, the difficulty of reusing the material eventually disposedwhen the adjustment of weighing can become a source of significant wastein the packaging process, incurring a higher cost of production in orderto overcome these wastes. For example, during the adjustment process inorder to reach the ideal value of mass for each package, it isinevitable, in the current model, the disposal of some packages, whosemasses are far from the value previously assigned. Thus, some packagesformed in the process are disposed, incurring not only in the eventualdisposal of products, but also in rejecting the packages used.

ANALYSIS OF STATE OF THE ART

Document MU8601890-6 advances a volumetric feeder for applicators andbagging equipments of granular products or powders with controlledvolume for solid products and can be applied to bag several solidproducts, with a predetermined dosage.

Patent PI0402405-2 exposes a volumetric feeder to dose precisely andtransporting microgranulate material and microspheres, with theadjustment of the screw in relation to the appropriate feeding tube tomaintain its speed ratio.

Document PI8405869-2 reveals the process and control and command deviceof filling containers, comprising a scale and a volumetric feeder ofcylindrical glassware. The piston rod of the cylinder is actuated by acam possibly comprising an adjustable portion, with the interposition ofelastic means in the path of a container to a filling station. Thefollowing operations take place: adjustment of the empty container whilefilling the volumetric feeder with a volume of product higher than apassword value; transfer of the product contained in the volumetricfeeder of the feeder to the recipient and continuous weighing until theproduct weight inside the container has reached the password value, theblocking of the piston rod, consecutively to the termination of thedispensing orifice of the volumetric feeder is modified so that thebreakpoint of the filling occurs between two specified points of thecam.

Document EP 0147263 (A1) anticipates a method and apparatus to check andcontrol the filling of containers for a given mass of product, theapparatus being provided with a carousel filled with various fillingpoints, each with a volumetric feeder with a timer or a feeder, whereinsome of the items include a balance, wherein the steps include: (i)weighing the empty container, simultaneously filling the volumetricfeeder, (ii) transfer of the volume contained the volumetric feeder,(iii) weighing the container filled and (iv) comparison after thecontainer tare.

The document EP 0120778 (A1) discloses a process and device for fillinga recipient, with a step of volumetric dosage associated to a stage ofweighing.

BRIEF DESCRIPTION OF THE INVENTION

This invention describes a dosing system applied to an automaticpackaging machinery, capable of measuring the mass of solids in bulk andadjust the final mass of the package to be baled so that the averagemasses of each package result in a pre-set value, as well as thestandard deviation of the masses average results in a value within atolerance range determined in advance.

It also describes a control system of supply of particular products,associated with the device for measuring weight applied to an automaticpackaging machinery, which monitors the mass allocated in each packet tocheck any shortage or excess weight in the package being formed,allowing the compensation of this difference throughout the packagedbatch or the bale to be formed, while keeping the average masses of thebatch packages within the values, indicators and technical criteriaestablished in advance, through the handling of the individual elementof the particulate material being packaged.

Moreover, it outlines a control system for the mass of particulatesolids articles to be packaged in automatic packaging machinery, whichprovides conditions for monitoring the mass that composes each packagein order to control the average package of the batch to be packed or thebale to be formed.

This system performs the monitoring of the mass inserted in each formedpackage, associated with the device that measures the primary volume ofthe material to be packed, making it possible to identify the differencein the amount previously determined to be packaged so that it canperform the adjustment of the primary volume to the next measurement,approximating the amount desired, and thus minimizing the differencebetween the measured and desired value.

If compared with those comprised in the state of the art, thisinnovation greatly improves a number of problems, especially with regardto measurement effectiveness of packaging machines since the system formass control, combined with measurement devices, account for effectivelyquantities of particulate products, surplus or missing, compensatingthroughout the packaging process of the product batch and ensuring thatthe mass of each package should be as close as possible to the limit,minimizing the common standard deviation for such equipment.

These meters enable the continuous adjustment of the mass of thepackages that are being sequentially formed by a packaging machinery, soas to maintain the standard deviation of the mass of the packets formedwithin a range previously established and with a high degree ofaccuracy.

DESCRIPTION OF FIGURES

FIG. 1 shows a perspective frontal view of the packaging machinerymechanism, wherein the volumetric feeder (1), primary mass meters (2),secondary mass meters (3), particle selectors (4) and packaging funnel(5) are noticed.

FIG. 2 shows a perspective rear view of the packaging machinerymechanism, wherein the volumetric feeder (1), primary mass meters (2),secondary mass meters (3), particle selectors (4) and packaging funnel(5) are noticed.

DETAILED DESCRIPTION OF THE INVENTION

This invention outlines a control system for the mass of theparticle-solid articles to be packaged in packaging machineryautomatically, which provides conditions for monitoring the mass thatcompound each package in order to control the average package of thebatch to be wrapped or bale to be formed.

This system performs the monitoring of the mass inserted in each packageformed, associated to the device that measures the primary volume of thematerial to be packaged, making it possible to identify the differencein the amount previously determined to be packaged so that it canperform the adjustment of the primary volume to the next measurement,approximating the amount desired, and thus minimizing the differencebetween the measured and desired value.

Therefore, the system has a volumetric feeder (1) that performs a firstinput of product to be packaged to the primary meter (2), whichperceives the mass of the volume contributed and fixes, if necessary,the adjustment of the volumetric feeder (1), effecting the correctionaccording to the measured mass. That is, in case of excess weight inrelation to the predetermined value, the primary mass meter (2) controlsthe proportional reduction of the volume to be accommodated by thevolumetric feeder (1), and, if the measured mass is below the valuepreviously determined, the primary mass meter (2) controls theproportional increase in the volume to be accommodated by the volumetricfeeder (1). Thus, the subsequent volume to be accommodated by thevolumetric feeder (1) is already set in relation to the mass desired,reducing the need for correction to be performed by the primary massmeter (2).

In order to adjust the weight to be packaged, approximating it to thevalue previously set, a second device for measuring mass (3) isassociated with the control system, making the final correction of themass of the package to be formed in association with a particle deviceselector (4), capable of provisioning each individual particle of thesolid material to be packed. Thus, the particles are added to the masscontained in the secondary mass meter (3), performing a fine tuning ofthe package mass formed until forming the desired mass.

Eventually, the mass to be added, i.e. the mass of each particle isgreater than the difference between the value of the mass of the packageand the desired amount to complete the package mass. In this case, thesystem automatically chooses between adding the particle mass to thepackage, even if the value is exceeded, and not adding the particle,leaving the package with a mass slightly smaller than the saidstipulated amount. In both cases, the system stores information aboutthe differences of mass accumulated in order to compensate thedifference over the batch to be formed by packages.

The compensation of the mass difference of packages, along the batch tobe formed, is made possible by the combination of the particle massmeasurement value, the mass value of the package under formation and thevalue of the difference of accumulated mass when forming the package.The dosage system has the ability to perceive the need to add theparticle in each package, compensating the difference of accumulatedmass so that its value is maintained low, tending to zero.

For example, when adding the particle result in exceeding the defaultvalue of the mass of the package, there is a decision to be made, whichdepend on the value package mass at that time. If the mass of thepackage is below the limit of standard deviation established, the device(4) promotes the aggregation of the particle to the package, slightlysurpassing the value of the standard mass of the package. However, ifthe mass of the package is within an acceptable level, the device (4)can avoid sending such particle to the package, which would be with alower value than the default, but within an acceptable margin. In bothcases, information about the difference of the mass of the packageagainst the default value would be stored for consideration of thecomposition of the next packet, so that the average mass of the formedpackages are better controlled throughout the batch packaging or thebale under formation.

Another significant aspect of this invention relates to the possibilityof reducing operating costs, since the dosage system of the presentinvention allows the formation of packets to take place only after theproper weighing of the contents to be packed, focusing on the netweight, unlike the existing models, which consider the gross weight.

Further, the proposed system allows the material eventually disposedwhen the mass of the packages is corrected can be reused directly in thepackaging process, since it allows for the disposal of the materialbefore the formation of the package.

This invention is not limited to the representations mentioned orillustrated herein, and it has to be comprehended in its wide scope.Many changes and other representations of the invention will come inmind of those skilled in the technique to which this invention belongs,having the learning benefit presented in previous descriptions andattached drawings. Further, it is to be understood that the invention isnot limited to the disclosed specific shape and that changes and othershapes are understood as enclosed within the scope of the attachedclaims. Although specific terms are nominated herein, they are only usedin a generic and descriptive form and not for a limiting purpose.

1. A dosage system for the packaging of solid products said systemcomprising packaging machinery comprising a primary mass meter (2) incommunication with a volumetric feeder (1) and a secondary mass meter(3) in communication with particle selector (4) which enable thecontinuous adjustment of the mass of the packages that are beingsequentially formed by the packaging machinery, to keep the standarddeviation of the mass of the packages formed with a predetermined range.2. The dosage system of claim 1, further comprises a device formeasuring the individual mass of the particle of the solid product to bepacked in a packaging machinery, said system further comprising a meansfor determining the difference in mass for a given package in relationof the desired value for compensation throughout the batch to be packedin said packaging machinery.
 3. The dosage system of claim 1, whereincommunication between the primary mass meter (2) and the volumetricfeeder (1) occurs through a specific computer application that adjuststhe volume the volume of material obtained from the volumetric feeder(1), to provide a mass previously established for each package.
 4. Thedosage system of claim 1, wherein communication between the secondarymass meter (3) and the particle selector (4), occurs through a specificcomputer application that adjusts the amount of particles contributed bysaid particle selector (4) to provide the mass of previously establishedfor each package.
 5. The dosage system of claim 1, said system furthercomprising a means for enabling the reuse of material disposed duringcorrection procedures of the mass of the package before the formation ofsaid package, directly in the packaging process, minimizing operatingwaste and, consequently, the costs of the packaging process.